Pill or tablet formulation has been conveniently and practically used for a long time in order to administer a drug to the body. However, it has been known that a surprising number of people have trouble in swallowing pills. In addition, the tablet formulation type is inconvenient for old people who have hand tremors or dysphagia; infants and young children who cannot swallow pills, and thus need to take pills in syrup form or take pills by crushing and mixing them with water; people in a situation in which drinking water is difficult to get, such as while traveling; water-restricted patients (for example, nephropathy patients); patients who lie down continuously, and thus have difficulty in sitting up to take medicine; and the like.
Fast-disintegrating tablets have been developed to improve the above problems. Fast-disintegrating tablet is one type of tablet which disintegrates in the oral cavity in several seconds to several tens of seconds by saliva upon putting the tablet in the mouth, and thus may be taken without water. Fast-disintegrating tablet is known by several names, such as “orally disintegrating tablet,” “rapidly melting tablet,” “orodispersible tablet,” “fast-dissolving tablet,” “rapidly eroding tablet,” etc. Fast-disintegrating tablet is useful for some mental patients other than the subjects mentioned above; there are cases in which they pretend to eat in front of a nurse, hiding a tablet under his/her tongue, and then spitting out the tablet when the nurse is absent, so fast-disintegrating tablet is a useful dosage form to ensure the administration of medicine.
Ideal fast-disintegrating tablets disintegrate quickly and softly in the oral cavity and have physical properties suitable for production, transportation, packaging, storage, etc.—for example, high hardness and low friability. Unfortunately, fast-disintegrating tablets generally have poor physical properties; on the other hand, tablets with good physical properties generally have poor disintegration. Most commercially available fast-disintegrating tablets find a balance or compromise among these needs; or they focus on one aspect, while the shortages are attributed to consumers—for example, by issuing precautions; or they are supplemented in another way, such as specialty packaging.
The known methods for manufacturing fast-disintegrating tablets include a method using freeze-drying; a method similar to a cotton-candy-making process; a method to contain an appropriate amount of foaming agent in tablets; a method using a large amount of disintegrating agent; a method using an appropriate combination of highly soluble saccharide and highly modable saccharide; a method for improving the physical properties by humidifying or heating the tablet obtained by low-pressure tableting; a method for tableting a mixture which hardly contains a lubricant without problems by using an improved tableting machine in which a lubricant is sprayed into a mold where a tablet is formed; etc.
However, many of the above manufacturing methods require special equipment or high-priced facilities; or general pharmaceutical equipment cannot be used as it is, and thus has to be modified, and which may cause a rise in the production cost or restrict various applications. In addition, the tablets which need a specific humidity and temperature conditions at or after tableting may be exposed to harsh conditions or require unnecessary investments in equipment, which may limit applications.
Korean Patent No. 0642976 discloses a method for manufacturing a fast-disintegrating tablet, comprising tableting after granulating a drug, diluent and saccharide having a relatively low melting point; heating over the melting temperature at which the saccharide having a low melting point is melted; and cooling. However, the method includes a heating step, wherein the formed tablet is placed in a 120-160° C. oven for several minutes, and thus has a limitation in that it cannot be used for drugs unstable to high temperature.
Korean Patent No. 0655627 discloses a fast-disintegrating tablet which comprises saccharide and amorphous saccharide, and is manufactured by humidifying and drying after tableting. According to the examples of the above patent, a formed tablet was placed in a 35° C., 85% RH thermohygrostat for 20 minutes and then dried in a 50° C. oven for several tens of minutes; or was placed in a 25° C., 70-80% RH thermohygrostat for 12-24 hours and then dried at 25 to 40° C. for several hours. Consequently, this method is difficult to apply to drugs unstable to moisture and requires cumbersome processes after tableting.
Therefore, there has been a continuous need to develop a fast-disintegrating tablet having fast disintegrability as well as high hardness which can be manufactured without modifying the tableting machine or forming machine conventionally used in a pharmaceutical manufacturing process and without using additional equipment; and a process for manufacturing the same not requiring cumbersome post-treatment processes under harsh conditions after the tableting or forming step.